The present invention relates to shock-absorbing devices and, more particularly, to such a shock-absorbing device, which comprises a plurality of compressible springy balls of rubber. Plastics or silicon rubber material connected in series or parallel in a cylindrical casing to absorb or lessen the pressure.
Various shock-absorbing devices have been disclosed for use in bicycles, vessels, aircrafts, trains, cars, motorcycles, engineering machinery, industrial equipment, building construction equipment and etc. These conventional shock-absorbing devices commonly use shock-absorbing springs, shock absorbing elastomer, and hydraulic or pneumatic shock absorbing cylinders to absorb or lessen the pressure. However, these conventional shock-absorbing devices are still not satisfactory in function because of the following drawbacks:
a. Elastic fatigue, metal aging, and breaking problems tend to occur quickly with use;
b. Fluid or air leakage may occur, affecting the shock absorbing performance;
c. Attenuation of damping effect tends to occur;
d. Breakdown tends to occur upon an overload;
e. Bulking and heavy;
f. Limited buffering stroke;
g. Difficult to be standardized;
h. Load bearing and stroke range adjustment not applicable; and
i. High cost.
Further, in building and bridge construction, lead-core rubber bearing cushions, laminated rubber bearing cushions, rubber bearing cushions of high damping coefficient are commonly used to lessen static force, dynamic force and earthquake shockwaves. However, these devices do not return to their former shape quickly after deformed by an external force.
The present invention has been accomplished to provide a shock-absorbing device, which eliminates the aforesaid drawbacks. According to one aspect of the present invention, the shock-absorbing device is developed subject to Boyle""s law: the product of the pressure and the specific volume of a gas at constant temperature is constant.
According to another aspect of the present invention, the shock-absorbing device comprises an airtight cylindrical casing; at least one compressible springy ball arranged in the cylindrical casing; a main piston mounted in the cylindrical casing above the at least one compressible springy ball and reciprocated to compress the at least one compressible springy ball, the main piston having a piston rod extended out of the cylindrical casing; a damping substance flowing in the cylindrical casing; and a plurality of main piston valves respectively installed in said main piston for enabling the damping substance to flow between an upper chamber in the cylindrical casing above the main piston and a lower chamber in the cylindrical casing below the main piston. According to another aspect of the present invention, the compressible springy balls can be arranged in series, or alternatively in parallel in the cylindrical casing. According to still another aspect of the present invention, the compressible springy balls are made of elastic plastic or rubber material, or silicon rubber.